Emulsion fuel and method of preparing the same

ABSTRACT

The emulsion fuel according to the present invention is prepared by emulsifying about 55 to 90% by weight of a mixture of heavy oil, 45 to 10% by weight of water, and 0.3 to 0.8% by weight of a catalyst. The catalyst comprises caustic soda (sodium hydroxide) and calcium dichloride in half and half. The calcium chloride can be partly substituted with calcium sulfate.

FIELD OF THE INVENTION

The present invention relates to an emulsion fuel prepared by addingwater to common heavy oil such as bunker fuel oil C and petroleum. Moreparticularly, the present invention relates to an emulsion fuel as analternative energy fuel by emulsifying common heavy oil with a catalystafter adding water to the heavy oil.

BACKGROUND OF THE INVENTION

There are a lot of efforts and developments in the world to lessen anamount of sulfur in a fuel and to convert a solid fuel to a liquid orgaseous fuel in view of saving energy and preventing air-pollution.Specially, the air-pollution caused by a petroleum fuel is very seriousdue to its harmful influence on an ecosystem. Although there areinvisible trade barriers with WTO (World Trade Organization), OECD(Organization for Economic Cooperation and Development) and GR (GreenRound) founded or contracted, the developments for suitable alternativefuels are not sufficient.

The emulsion fuel made by adding water to fuel oil has been studied inEurope since around 1950 and then started the trial to improvecombustibility and save fuel. Recently, in regard to the emulsion fuelthere are so many researches in U.S.A. and Japan.

During World War II, using aviation gasoline to which added water theairplane engine produced strengthened output. There are so manypossibilities for reducing the air-pollution and improving combustionefficiency by studying and testing the emulsion fuel.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide a novel emulsionfuel having a good effect on reduction of energy consumption andprevention from anti-pollution by emulsifying fuel by means of addingwater to common fuel oil (heavy oil) applied to an industrial boiler orfurnace.

Another object of the present invention is to provide an emulsion fuelthat can prevent air-pollution and obtain commercial benefit bydissolving sludge contained in heavy oil minutely, burning theemulsified fuel oil that is made by the added water beingultra-particles and then facilitating complete combustion throughhydrogen gas reaction and fine explosion.

Still another object of the present invention is to provide an emulsionfuel that can prevent air-pollution and dispense with fuel by preventingsmoke, dust, carbon monoxide, hydrocarbon and so on from being formed bydecreasing excess air rate, and can lessen conversion rate of SO₂ toSO₃, and change combustion flame to white-hot and increasing radiationheat.

Still another object of the present invention is to provide a method ofpreparing the emulsion fuel.

Other objects and advantages of this invention will be apparent from theensuing disclosure and appended claims.

SUMMARY OF THE INVENTION

The emulsion fuel according to the present invention is prepared byemulsifying about 55 to 90% by weight of a mixture of heavy oil, 45 to10% by weight of water, and 0.3 to 0.8% by weight of a catalyst. Thecatalyst comprises caustic soda (sodium hydroxide) and calciumdichloride in half and half. The calcium chloride can be partlysubstituted with calcium sulfate.

DETAILED DESCRIPTION OF THE INVENTION

The emulsion fuel according to the present invention stems from greenpine leaves that commonly used as a winter fuel in some agriculturaldistricts of Korea. The green pine leaves comprise 90% of water, and 10%of pine oil and other minimal organic combustibles. Because the greenpine leaves burn very actively and have a high thermal efficiency duringcombustion, they are suitable for the Korean under-floor heating system.

Just as the green pine leaves comprises 10% of pine oil and 90% ofwater, the emulsion fuel of the present invention can be prepared byemulsifying common heavy oil such as bunker fuel oil C with water. Also,the catalyst compound of the present invention have invented owing tothe property that a sodium hydroxide can be soluble oil in water andthat calcium or bittern containing the calcium solidify proteins. Byusing the catalyst compound, a mixture of heavy oil and water can beemulsified in the present invention.

For example, the green pine leaves in which 10% of pine oil in 90% wateris dissolved can be easily burned and have a good efficiency. However,in case of permeating 50% of water into completely dried pine leaves,the leaves did not get even ignited. The reason is that the permeated50% of water exists as water itself, not a soluble compound of pine oiland water as in case of the green pine leaves.

The compound prepared by mixing 10 to 45% by weight of water and 90 to55% by weight of heavy oil such as bunker fuel oil C and petroleum inthe presence of the catalyst in accordance with the present invention iskind of combustible material different from water. The moleculestructure of the catalyst comprises an alkyl part that is affinitivewith oil and a part that is affinitive with water, that is, the catalysthas both a hydrophobic and a hydrophilic group. Thus, between an oillayer and a water layer, because of the catalyst having a hydrophobicgroup and a hydrophilic group, hydrophobic molecules is placed at theoil layer, hydrophilic molecules at the water layer by attraction force.In consequence, the emulsification occurs to change properties of aninterface or surface of water and oil by surface activities.

The catalyst of the present invention is composed of sodium hydroxideand calcium dichloride. The calcium dichloride can be partly substitutedby calcium sulfate. Adding 50% of a sodium hydroxide aqueous solutioninto 50% of a calcium dichloride slowly through a netting fabric, awhite compound whose shape is like a thickening agent is educed bychemical interaction between the sodium hydroxide and calciumdichloride. Drying the compound on a netting thread having good waterpermeability, it becomes minute powders that have no tastes.

The emulsion fuel according to the present invention is prepared byemulsifying with mixing 55 to 90% by weight of heavy oil such as bunkerfuel oil C and petroleum and 45 to 10% by weight of water, and adding0.3 to 0.8% by weight of catalyst. Adding 45 to 10% by weight of waterand the catalyst to fuel oil, the water is changed into minute dropletshaving less than 10 micron of diameter and the water becomes waterdroplets in oil. With the water droplets contained in the jetted oildroplet being heated and expanded in a furnace, the water droplets arevaporized explosively, disperse the emulsion fuel in all directions andthen can facilitate complete combustion of fuel.

In general, the ultra-particle sized emulsion fuel can burn completelyby reducing an amount of excess water and increasing the contact surfacearea. And, a cooling reaction of fire by the latent heat caused byvaporization of water, and a reaction to carbon of water bring toreductive effect of combustion carbon. Also, the contents of NO_(x) andhydrocarbon are reduced by chemical and physical reaction thereof. Theemulsion fuel has an excellent fuel supplying and jetting as a colloid.

When the emulsion fuel that contains oil and water droplet burns, thewater droplet contained in the oil droplet is exploded and vaporizedwith being heated at high temperature and expanded rapidly. Then thewater droplet is continuously exploded, the ambient fuel is dispersedminutely in all directions. Thus, the continuous minute explosivereaction brings complete combustion of the fuel.

The water droplet of the emulsion fuel has a diameter of about 10microns, 10 to 30% of water, and many of microns of water droplets inoil droplets. For example, the number of water droplets having diametersof 3 microns is about 900 when 50 microns is a diameter of an oildroplet of the emulsion fuel whose water contents are 20%.

In case of LPG, the combustion gas includes 19 to 20% of water and thatis similar with the emulsion fuel. The combustion efficiency of thepresent emulsion fuel is even higher than that of LPG gas.

The reaction formula of the water is C+H₂O→CO+H₂(+O₂)→CO₂+H₂O, and thatis the reaction of water gas. Water molecules react with fuel oil athigh temperature and then CO and H are generated. The combustionefficiency increases due to the reduction of the carbons.

An oxidized nitrogen generated in combustion is almost NO and NO₂. BothNO and NO₂ are called NO_(x). The water of the emulsion fuel havinguniform particles, it prevents generation of local high temperatureregion and decreases combustion temperature by means of vaporizationlatent heat of 20 to 30% by volume of water. The water particles thenprevent generation of NO_(x) with absorption of heat, and generation oflocal high temperature region by reaction of carbon particles and watergas. This NO_(x) reduction results in prevention of air-pollution.

When the emulsion fuel of the present invention is applied to domesticor industrial boilers, NO_(x) generation can be reduced by 40 to 75%.The expanded surface areas of the particle sized water dropletfacilitate air-contact, and complete combustion can be accomplished witha little air contents and practically more than 50% of smoke is reduced.Also, the concentration of smoke dusts is also reduced. For the mostpart, adding 50% of water decreases the concentration of smoke dusts byhalf. The emulsion fuel of the present invention can reduce pollutionbecause of remarkable reduction of smoke and can reduce the energy fuelby 30% because of reduction of the excess air rate.

Generally, gas fuel burns with a transparent flame and heavy oil burnswith a transparent and yellow flame, which is in the presence offloating carbons. However, the present emulsion fuel burns like the gasfuel with a flame.

Adding water to fuel oil, an amount of combustion gases increase bymultiplying a weight of added water by 22.4/18 (Nm³/kg). A temperatureof the flame is decreased by about 100° C. when water is added by 30 to50% based on combustion with 1.2 of lamp-oil over air. However, becausethe amount of combustion gases increase, a heat transfer effect is notdecreased. The combustion gases generated by combustion of liquefiedfuel (e.g. LPG or LNG) include about 13% of water. By adding water tothe fuel the water contents become 16 to 17%. The emulsion fuel has nocorrosion problem because the liquefied fuel that contains similarconcentration of water with that of the emulsion fuel has no such kindof problem. Although there is little heat loss occurred by the addedwater, the thermal efficiency is increased owing to the decrease of airrate, smoke, pollution and so on, and the effect that can prevent NO_(x)from being generated.

The emulsion fuel is dispersed in a burner actively and the rate of thecombustion gets more faster since combustion flames of oil droplets thathave ultra-particles with water becomes a single flame. Because the fuelbecomes more minute particles and then is dispersed again, the particlesof the water is exploded continuously by high temperature. Thus,complete combustion can be accomplished by forming combustion flame likecomplete particle gases.

The present invention may be better understood by reference to thefollowing examples that are intended for the purpose of illustration andare not to be construed as in any way limiting the scope of the presentinvention, which is defined in the claims appended hereto. In thefollowing examples, all parts and percentage are by weight unlessotherwise indicated.

EXAMPLES Example 1

After mixing 60% by weight of bunker fuel oil C containing less than0.5% of sulfur with 40% by weight of water, 0.5% by weight of catalystcompound was added based on the weight of the entire composition. Thecatalyst compound comprised caustic soda and calcium dichloride in halfand half. The present emulsion fuel was prepared by emulsifying themixed composition using an emulsifier.

Example 2

The Example 2 was put to the test in the same manner as in Example 1,except that 70% by weight of bunker fuel oil C and 30% by weight ofwater were used.

Comparative Example 1

The emulsion fuel was prepared with no water and 1.0% by weight ofsulfur was used.

Comparative Example 2

The emulsion fuel was prepared with no water and less than 0.5% byweight of sulfur was used.

The test was performed with a smoke tube packaged boiler continuouslyoperated under more than 90% of loading rate. The analyses for theemulsion fuel and air-pollutants was carried out and the volume of thesupplying oil, the exhaust gas and so on were measured. The analyzedresults regarding Example 1 and 2, and Comparative Example 1 and 2 wererecorded on the below Table 1, and the performances on the below Table2. The tables showed that the emulsion fuel according to the presentinvention, such as Example 1 and 2, had good results and performances.TABLE 1 Comparative Example Example Analyzed subjects Unit 1 2 1 2Higher calorific value kcal/kg 8,940 9,720 10,300 10,520 Water contentvol. % 12.0 7.0 3.2 below 0.05 Dynamic viscosity 40° C., cSt 385 308 308287 Residual carbon powder wt, % 3.94 5.11 7.21 6.53 Specific gravity15/4° C. 0.9559 0.9496 0.9541 0.9453 Ash contents wt, % 0.29 0.21 0.0130.002 Sulfur contents wt, % 0.41 0.42 0.77 0.49 Metal Cadmium (Cd) Ppm —— — — Contents Lead (Pb) Ppm — — — — Chrome (Cr) Ppm — — below 1 —Arsenic (As) Ppm — — — — Calcium (Ca) Ppm 20 49 2 — Magnesium (Mg) Ppm26 12 below 1 below 1 Phosphorus (P) Ppm — — — — Zinc (Zn) Ppm 1 1 1 1

TABLE 2 Comparative Example Example Measured subjects Unit 1 2 1 2 Fuelconsumption L/Hr 260 259 247 249 Supplying oil temperature ° C. 89 89 8989 Specific gravity of fuel oil 15/4° C. 0.9559 0.9496 0.9453 0.9541Converted fuel consumption Kg/Hr 236 233 222 226 Supplying water flowrate L/Hr 2,982 3,074 3,134 2,880 Supplying water temperature ° C. 17 2019 20 Specific gravity of Kg/m³ 998.7 998.2 998.4 998.2 supplying waterConverted vaporization Kg/Hr 2.978 3.068 3.129 2.875 Vapor pressureKg/cm² 3.2 3.2 3.3 3.2 Exit temperature of a boiler ° C. 244 252 244 240Exhaust Gas temperature ° C. 228 238 217 220 Gas O2 contents % 2.82 2.142.69 2.85 (at the Fixed pressure mmH₂O −1.5 −1.5 −1.0 −1.3 exit of aDynamic pressure mmH₂O 5.3 5.1 5.2 5.2 multi- Gas density Kg/m³ 0.7080.695 0.72 1 0.720 cyclone) Gas velocity m/sec 10.18 10.08 10.02 10.00Cross-sectional m² 0.16 0.16 0.16 0.16 area of a duct Gas flow ratem³/hr 5,860 5,810 5,770 5,760 Nm³/hr 3,190 3,100 3,210 3,190

The present invention can provide an emulsion fuel having a good effecton reduction of energy consumption and prevention from anti-pollution byemulsifying fuel by means of adding water to common fuel oil applied toan industrial boiler or furnace. Also, the present emulsion fuel canprevent air-pollution and obtain commercial benefit by dissolving sludgecontained in heavy oil minutely, burning the emulsified fuel oil that ismade by the added water being ultra-particles and then facilitatingcomplete combustion through hydrogen gas reaction and fine explosion.

While the present invention has been described with reference to theparticular illustrative embodiments, it is not to be restricted by theembodiments but only by the appended claims. It is to be appreciatedthat those skilled in the art can change or modify the embodimentswithout departing from the scope and spirit of the present invention.

1. An emulsion fuel comprising 55 to 90% by weight of a heavy oil, 45 to10% by weight of water, and a small amount of a catalyst.
 2. Theemulsion fuel as defined in claim 1, wherein said catalyst is preparedby mixing caustic soda with calcium dichloride.
 3. The emulsion fuel asdefined in claim 2, wherein said catalyst comprises 50% by weight ofcaustic soda and 50% by weight of calcium dichloride.
 4. The emulsionfuel as defined in claim 2, wherein said calcium chloride is partlysubstituted with calcium sulfate.
 5. The emulsion fuel as defined inclaim 1, wherein said catalyst is 0.3 to 0.8% by weight.
 6. The emulsionfuel as defined in claim 1, wherein said heavy oil is bunker fuel oil Cor petroleum.
 7. A method for preparing an emulsion fuel comprising thesteps of: mixing a composition comprising 55 to 90% by weight of a heavyoil, 45 to 10% by weight of water with a small amount of a catalyst; andemulsifying the mixture with an emulsifier.
 8. The method as defined inclaim 7, wherein said catalyst is prepared by mixing caustic soda withcalcium dichloride.
 9. The method as defined in claim 8, wherein saidcatalyst comprises 50% by weight of caustic soda and 50% by weight ofcalcium dichloride.
 10. The method as defined claim 8, wherein saidcalcium chloride is partly substituted with calcium sulfate.
 11. Themethod as defined claim 7, wherein said catalyst is 0.3 to 0.8% byweight.
 12. The method as defined claim 7, wherein said heavy oil isbunker fuel oil C or petroleum.
 13. A catalyst composition for preparingan emulsion fuel by emulsifying a mixture of a heavy oil and water, thecomposition comprising 50% by weight of caustic soda and 50% by weightof calcium dichloride.
 14. A catalyst composition for preparing anemulsion fuel by emulsifying a mixture of a heavy oil and water, thecomposition comprising 50 parts by weight of caustic soda and 50 partsby weight of a mixture of calcium dichloride and calcium sulfate.